(plural, nucleoli) A specialized structure in the nucleus, formed from various chromosomes and active in the synthesis of ribosomes.

Nucleosome

The basic, beadlike unit of DNA packaging in eukaryotes, consisting of a segment of DNA wound around a protein core composed of two copies of each of four types of histone.

Nucleus

(1) An atom's central core, containing protons and neutrons.

(2) The chromosome-containing organelle of a eukaryotic cell.

nuclear lamina

The nuclear Lamina lines the the nuclear envelope it is made of a lattice/net of protein filaments which provide support for the nucleus and anchorage points for chromosomes.

Nuclear envelope

The membrane in eukaryotes that encloses the nucleus, separating it from the cytoplasm.

nuclear pore complex

The nucleus has a double membrane (nuclear envelope) surrounding it. This is continuous with the endoplasmic reticulum and is studded with nuclear pores, each of which has a distinctive ring of proteins surrounding the pore.

Organelle

One of several formed bodies with specialized functions, suspended in the cytoplasm of eukaryotic cells.

Peroxisome

A microbody containing enzymes that transfer hydrogen from various substrates to oxygen, producing and then degrading hydrogen peroxide.